[nrf noup] cmake: Ensure that 4 variables are initialized before de-r…

…eferenced

In a multi-image build variables must be initialized before they are
de-referenced or else values from one image may accidentally affect
another image.

Signed-off-by: Sebastian Bøe <[email protected]>

CMakeLists.txt

@@ -354,6 +354,9 @@ zephyr_cc_option(-fmacro-prefix-map=${ZEPHYR_BASE}=ZEPHYR_BASE)
 
 # Declare MPU userspace dependencies before the linker scripts to make
 # sure the order of dependencies are met
+unset(APP_SMEM_ALIGNED_DEP)
+unset(APP_SMEM_UNALIGNED_DEP)
+unset(PRIV_STACK_DEP)
 if(CONFIG_USERSPACE)
   set(APP_SMEM_ALIGNED_DEP ${IMAGE}app_smem_aligned_linker)
   set(APP_SMEM_UNALIGNED_DEP ${IMAGE}app_smem_unaligned_linker)
@@ -660,6 +663,7 @@ endforeach()
 
 get_property(OUTPUT_FORMAT        GLOBAL PROPERTY PROPERTY_OUTPUT_FORMAT)
 
+unset(CODE_RELOCATION_DEP)
 if (CONFIG_CODE_DATA_RELOCATION)
   set(CODE_RELOCATION_DEP ${IMAGE}code_relocation_source_lib)
 endif() # CONFIG_CODE_DATA_RELOCATION